JPH10299548A - Electronic governor device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic governor device for an internal combustion engine having good responsiveness and high stability of a rotational speed. SOLUTION: This electronic governor device for an internal combustion engine is provided with a phase difference detector 24 outputting a phase difference signal displaying a phase difference between a rotational speed detection signal output by a rotational speed detector 3 detecting a rotational speed of an internal combustion engine 1 and a target rotational speed signal output by a target rotational speed setter 4, frequency deviation detector 23 outputting a frequency deviation signal displaying a frequency deviation between the rotational speed detection signal and the target rotational speed signal, arithmetic circuit 25 generating a control signal Q changing a level in accordance with changing of the phase difference signal and the frequency deviation signal, and a drive part 6 giving a drive current Id modulated by the control signal Q to an actuator 8. Here, so as to fix a phase difference between the rotational speed detection signal and the target rotational speed signal, the actuator 8 is controlled, a rotational speed of the engine is conformed to a target rotational speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic governor for an internal combustion engine that controls the rotational speed of the internal combustion engine to be equal to a target rotational speed.

[0002]

2. Description of the Related Art In an internal combustion engine drive generator (engine generator) used for supplying AC power of a commercial frequency, it is necessary to keep the rotation speed of the internal combustion engine at a target rotation speed.
In order to supply high-quality electric power with little frequency fluctuation, it is necessary to make the rotation speed fluctuation of the internal combustion engine as small as possible. Therefore, an internal combustion engine that drives an AC generator is provided with an electronic governor device that performs feedback control of the rotation speed, and is operated so that the rotation speed matches the target rotation speed.

[0003] In recent years, cogeneration systems for efficiently supplying power and supplying hot water have become widespread. In an internal combustion engine driven generator used in the system,
It is required that the fluctuation range of the output frequency of the generator be suppressed to ± 0.1 [Hz] or less. For this reason, the demand for an internal combustion engine having an electronic governor device has been increasing, and it has become necessary to increase the accuracy of rotation speed control by the governor device.

In an electronic governor for an internal combustion engine, a rotation speed detection signal obtained by converting an output frequency of a sensor for detecting the rotation speed of the internal combustion engine into a voltage signal is compared with a voltage signal indicating a target rotation speed. In general, the amount of fuel supplied to the engine is controlled so that the difference between the two signals becomes zero. For example, as shown in FIG. 5, an electronic governor device disclosed in Japanese Patent Application No. 2-277112 discloses a fuel supply amount adjusting device 2 that adjusts a fuel supply amount to an internal combustion engine 1 that drives a load.
A rotation speed detector 3 'for outputting a rotation speed detection signal Vn having a voltage value proportional to the actual rotation speed of the internal combustion engine 1; and a target rotation speed signal Vno having a voltage value proportional to the target rotation speed of the internal combustion engine. , And the amount of operation of the fuel supply amount adjusting device 2 required to make the actual rotation speed coincide with the target rotation speed by inputting the rotation speed detection signal Vn and the target rotation speed signal Vno. And a control operation unit 5 'for outputting a control signal Q for giving the operation amount, and supplying a drive current necessary for matching the actual rotation speed of the internal combustion engine to the target rotation speed with the control signal Q as an input. Driving unit 6 to be applied to the quantity adjusting device
'.

In the electronic governor shown in FIG. 5, a fuel supply adjusting device 2 includes a fuel supply adjusting means 7 such as a throttle valve for adjusting the amount of fuel supplied to the internal combustion engine 1.
And an actuator 8 which has an output unit which produces a displacement according to the magnitude of the applied drive current Id, and which operates the fuel supply amount adjusting means 7 by the displacement of the output unit. The rotational speed detector 3 'has a reluctor 3a1 and is mounted on a crankshaft of the engine. A signal generator for detecting a change in magnetic flux generated by the reluctor of the rotor and generating a pulse signal Pn. A well-known signal generator 3A having electrons 3b, and a frequency detection signal V obtained by converting the frequency of an output pulse signal of the signal generator 3A into a voltage signal.
Frequency / voltage converter (F / V converter) that outputs n
3B.

[0006] The target rotational speed setting device 4 'comprises resistors R1 and R
A voltage divider circuit for dividing a constant power supply voltage to output a target speed signal Vno having a voltage value proportional to the target speed of the engine. Further, the drive unit 6 'outputs a pulse width modulation signal generator 11 which outputs a pulse width modulation signal Vc of a repetitive waveform whose peak value or frequency changes according to the magnitude of the rotation speed detection signal Vn.
And the control signal Q obtained from the control operation unit 5 'and the pulse width modulation signal VC, and the period in which the control signal Q exceeds the pulse width modulation signal and the control signal Q A pulse width modulator 12 that outputs a signal of a pulse waveform whose state is different between the following periods as a pulse width modulation control signal Vq, and a pulse width modulation control signal that is input to set the actual rotation speed of the internal combustion engine And a drive circuit 13 for supplying a drive current necessary for matching the rotation speed to the actuator 8.

[0007]

As described above, when a frequency proportional to the engine speed is converted into a voltage signal to obtain a speed detection signal, a delay element of the F / V converter is required. There has been a problem that control stability is reduced due to a response delay due to the (charge / discharge circuit of the capacitor) and a ripple included in the output of the converter.

In the configuration shown in FIG. 5, the correspondence between the dial scale of the target speed setting device and the target speed signal changes due to the variation in the resistance value of the resistors constituting the target speed setting device 4 '. Therefore, fine adjustment must be performed for each product, which is troublesome.

An object of the present invention is to provide an electronic governor device for an internal combustion engine which can easily increase the stability of the rotational speed.

[0010]

SUMMARY OF THE INVENTION The present invention provides a fuel supply amount adjusting device for adjusting a fuel supply amount to an internal combustion engine for driving a load, and outputs a rotational speed detection signal indicating an actual rotational speed of the internal combustion engine. A rotation speed detector, a target rotation speed setting device that outputs a target rotation speed signal that gives a target rotation speed of the internal combustion engine, and an actual rotation speed that matches the target rotation speed by inputting the rotation speed detection signal and the target rotation speed signal. A control operation unit that outputs a control signal that gives an operation amount of the fuel supply amount adjustment device necessary to cause the control signal to be input, and a drive current that is required to match the actual rotation speed of the internal combustion engine to the target rotation speed by inputting the control signal. The present invention relates to an electronic governor device for an internal combustion engine, comprising: a drive unit provided to the fuel supply amount adjusting device.

In the present invention, as the rotation speed detector, a device which outputs a signal having a frequency proportional to the actual rotation speed of the internal combustion engine as a rotation speed detection signal is used. The signal of the corresponding frequency is configured to be output as the target rotation speed signal.

Further, the control operation unit basically converts the phase difference between the two signals obtained by digitally comparing the phase of the rotation speed detection signal and the phase of the target rotation speed signal with a D / A converter or the like. A phase difference detector that converts the phase difference signal into a signal and outputs the phase difference signal, and the phase difference between the rotation speed detection signal and the target rotation speed signal is reduced to zero or the phase difference is made constant by inputting the phase difference signal. And a control signal generation circuit that generates a signal whose level changes according to the phase difference signal as a control signal.

Although the basic configuration of the control operation unit is as described above, in order to reduce the synchronization pull-in time and prevent erroneous synchronization, a rotation speed detection signal and a target A frequency deviation detector that receives the rotation speed signal as input and converts the frequency deviation of both input signals into a voltage signal and outputs a frequency deviation signal is provided, and generates a control signal according to both the phase difference signal and the frequency deviation signal. It is preferable to make it possible. In this case, the control signal generation circuit receives the phase difference signal and the frequency deviation signal as inputs, sets the phase difference to zero or constant, and changes the level according to the phase difference signal and the frequency deviation signal so that the frequency deviation becomes zero. Is output as a control signal.

A phase difference detector for converting a phase difference obtained by digitally comparing the phase of a rotation speed detection signal and the phase of a target rotation speed signal into a voltage signal is a large delay element such as an F / V converter. Do not have. Therefore, by providing a control loop for controlling the phase difference between the rotation speed detection signal and the target rotation speed signal to be zero or constant as described above, it is possible to prevent a response delay that may cause a problem in the control system. be able to. Further, since the output of the phase difference detector does not include a ripple, it is possible to prevent the stability of the control from being impaired due to the input of the ripple to the control operation unit.

In addition to the phase difference detector, a frequency deviation detector is provided to control the phase difference between the rotation speed detection signal and the target rotation speed signal to be zero or constant, and to make the frequency deviation of both signals zero. In the case where the rotation speed of the internal combustion engine quickly approaches the set rotation speed by the control operation for reducing the frequency deviation to zero, the phase difference between the rotation speed detection signal and the target rotation speed signal is obtained. Is controlled so as to be zero or constant, the time required for the engine speed to settle to the target engine speed can be shortened. When only the control for matching the phase of the rotation speed detection signal with the phase of the target rotation speed signal is performed, the rotation speed detection signal is output even when the engine is rotating at twice the rotation speed of the target rotation speed. It is possible that the phase of the target rotational speed signal coincides with the phase of the target rotational speed signal, causing erroneous synchronization. However, if the control for reducing the frequency deviation to be equal to or less than the set range is used together as described above, Can be prevented.

When the control for reducing the frequency deviation to be equal to or less than the set range is used together, an F / V converter having a delay element is required. It works effectively when the rotational speed of the deviated engine approaches the target rotational speed, and has little effect on control during steady-state operation in which operation is performed near the target rotational speed. However, there is no adverse effect on the response during steady operation.

When the load of the internal combustion engine is an AC generator, the output frequency of the AC generator is proportional to the engine speed, so that a rotation speed detection signal is obtained from the output of the AC generator. The rotation speed detector can be constituted as follows. With this configuration, it is not necessary to provide a special detector for detecting the number of rotations, so that the configuration of the control system can be simplified.

When the rotation operation of the internal combustion engine is microscopically observed, the rotation speed of the crankshaft decreases as the piston of the engine rises toward the top dead center, and the piston explodes in the cylinder. In the process of descending toward the bottom dead center, the rotational speed of the engine increases and reaches a maximum value, so that the rotational speed of the crankshaft of the engine fluctuates finely under the influence of the combustion cycle of the engine. Therefore, if the rotation speed detector is configured to generate a large number of pulses per rotation of the engine, the phase of each of the large number of pulses generated during one rotation of the engine affects the effect of the combustion cycle of the engine. As a result, the rotation speed of the crankshaft fluctuates finely, and the microscopic change in the number of revolutions of the crankshaft is detected as it is. In particular, when the engine is running at a low speed, fluctuations in the rotation speed due to changes in the combustion cycle become large. Therefore, as described above, when a phase change in the rotation speed detection signal due to the change in the combustion cycle is detected, the control tends to be unstable.

In order to prevent such a problem from occurring, the rotational speed detector is configured to generate a rotational speed detection pulse equal to the combustion cycle fluctuation frequency of the internal combustion engine as a rotational speed detection signal, and to set a target rotational speed. Preferably, the number setting device is configured to generate a pulse signal having a frequency equal to the combustion cycle fluctuation frequency of the engine at the target speed as the target speed signal.

Here, assuming that the combustion cycle fluctuation frequency is fx, the number of cylinders of the engine is n, and the target rotational speed is No [rpm], one explosion occurs during two revolutions of the crankshaft.
In a cycle engine, the combustion cycle fluctuation frequency fx is given by the following equation.

Fx = (No / 60) × (n / 2) (1) In a two-cycle engine in which one explosion is performed per rotation, the combustion cycle fluctuation frequency fx is given by the following equation.

Fx = (No / 60) × n (2) Assuming that the target engine speed is 3600 [rpm], the combustion cycle fluctuation frequency of the four-cycle four-cylinder internal combustion engine is 12
0 [Hz], and the combustion cycle fluctuation frequency of the two-cycle four-cylinder internal combustion engine is 240 [Hz]. That is, in a 4-cycle 4-cylinder internal combustion engine, the target engine speed is set to 3
In the case of 600 [rpm], the frequency of the target speed signal is set to 120 [Hz], and the engine speed is set to 3600 [rp].
m] is equal to 120.
The rotation speed detector may be configured to be [Hz]. When the target engine speed is set to 3600 [rpm] in a two-cycle four-cylinder internal combustion engine, when the frequency of the target engine speed signal is 240 [Hz] and the engine speed is equal to 3600 [rpm]. The rotation speed detector may be configured so that the frequency of the rotation speed detection signal becomes 240 [Hz].

As described above, the rotation speed detector is configured to generate a rotation speed detection pulse having a frequency equal to the combustion cycle fluctuation frequency of the internal combustion engine, and is equal to the combustion cycle fluctuation frequency of the engine at the target rotation speed. If the target speed setting device is configured to generate a frequency pulse signal as a target speed signal, the phase of the speed detection pulse and the phase of the target speed signal (pulse) will always be at the same position of the piston. Thus, the rotation speed is controlled in comparison with the above, so that it is possible to prevent a minute change in the rotation speed at the time of cranking due to the fluctuation of the combustion cycle from affecting the control, and to stabilize the control.

In the case of a four-cycle engine, one for every two revolutions
As described above, if the rotational speed detector generates a rotational speed detection pulse having a frequency equal to the combustion cycle fluctuation frequency as described above, once every two rotations at the same position of the piston. A pulse for detecting the number of revolutions is generated. However, the present invention is not limited to such a case, and in the case of a four-cycle engine, the rotation speed detector is configured to generate a rotation speed detection pulse having a frequency twice the combustion cycle fluctuation frequency. Then, a rotation speed detection pulse may be generated at the same position of the piston for each rotation. In such a configuration, the condition for generating the rotation number detection pulse differs between the rotation in which the explosion is performed and the rotation in which the explosion is not performed. It has been confirmed that no stability phenomenon occurs. In particular, when the number of cylinders is large, the change in the number of revolutions of the crankshaft accompanying the change in the combustion cycle is small, so that a pulse for detecting the number of revolutions having a frequency twice as high as the combustion cycle fluctuation frequency is generated. Even if a rotation speed detector is configured to generate a rotation speed detection pulse at the same position of the piston each time, no major problem occurs.

As the rotational speed detector, a signal generator that generates a pulse signal at a predetermined rotational angle position of the crankshaft can be used regardless of the combustion cycle fluctuation frequency of the engine. It is preferable to use a signal generator that generates a rotation number detection pulse at a rate of one rotation per rotation or one rotation per two rotations. When such a signal generator is used as a rotation speed detector, the rotation speed detection pulse is always generated at a constant rotation angle position of the crankshaft, so that the rotation speed due to the fluctuation of the combustion cycle is microscopically measured. It is possible to prevent the change from affecting the control, thereby improving the stability of the control.

The signal generator includes a rotor equipped with one reluctor (inductor) and attached to the crankshaft of the engine, and detects a change in magnetic flux generated by the reluctor of the rotor to generate a pulse signal. A well-known signal consisting of generated signal emission can be used. When such a signal generator is used, when the reluctor passes through the position of the magnetic pole portion of the signal emission (when the reluctor starts facing the magnetic pole portion of the signal emission and ends the facing). Two pulse signals having different polarities are generated, and one of the two pulse signals is used as a rotation speed detection pulse.

When a signal generator that generates a pulse signal at a specific rotation angle position of the crankshaft of the engine is used as a rotation speed detector, one rotation speed detection pulse per one rotation of the crankshaft is used as described above. Is generated, the rotation speed detection pulse is generated at a constant rotation angle position each time, so that a microscopic change in the rotation speed due to a change in the combustion cycle of the engine does not affect the control. Can be

A signal generator rotor is mounted on a camshaft which rotates by 間 に during one rotation of the crankshaft, and the rotor of the signal generator is mounted at a rate of one rotation per rotation of the camshaft (one rotation per two rotations of the crankshaft). Also, when a pulse for detecting the number of revolutions is generated, the pulse is generated at a constant rotation angle position, so that the microscopic change in the number of revolutions accompanying the change in the combustion cycle of the engine is similarly controlled. Can not be affected.

The target rotation speed setting device is preferably configured to divide the output frequency of a reference oscillator whose frequency is controlled to be constant by a crystal oscillator or a ceramic oscillator to obtain a target rotation speed detection signal. .

With this configuration, it is possible to prevent the frequency of the target rotation speed detection signal from fluctuating due to a change in ambient temperature, a variation in circuit constants, and the like. Thus, fine adjustment at the time of product shipment can be omitted.

[0031]

FIG. 1 shows an example of the configuration of an electronic governor device for an internal combustion engine according to the present invention. In FIG. 1, reference numeral 1 denotes an internal combustion engine for driving a predetermined load, and reference numeral 2 denotes an internal combustion engine. A fuel supply amount adjusting device for adjusting a fuel supply amount, 3 is a rotation number detector for outputting a rotation number detection signal Vf having a frequency proportional to the actual rotation number of the internal combustion engine 1, and 4 is proportional to a target rotation number of the internal combustion engine. A target speed setting device that outputs a target speed signal Vfo of the selected frequency, 5 is required for inputting the speed detection signal Vf and the target speed signal Vfo to match the actual engine speed to the target speed. A control operation section for calculating an operation amount of the fuel supply amount adjusting device and outputting a control signal Q for giving the operation amount; and 6 for inputting the control signal Q to make the actual rotational speed of the internal combustion engine coincide with the target rotational speed. Drive current necessary for the fuel supply amount adjustment device 2 Is a driving section that gives.

The fuel supply amount adjusting device 2 generates a fuel supply amount adjusting means 7 such as a throttle valve for adjusting the fuel supply amount to the internal combustion engine 1 and a displacement corresponding to the magnitude of the applied drive current Id. An actuator 8 having an output section and operating the fuel supply amount adjusting means 7 by displacement of the output section. As the actuator 8, an actuator configured to displace an output arm (output unit) using an electric motor as a drive source or an actuator configured to displace a plunger or a rotating shaft (output unit) using an electromagnet as a drive source is conventionally used. However, any type of actuator may be used in the present invention.

In this example, it is assumed that the actuator 8 is configured so that the supply amount of fuel increases as the drive current Id applied to the actuator 8 increases.

The rotational speed detector 3 includes a rotor 3a having one reluctor 3a1 and mounted on the crankshaft of the engine.
And a signal generator 3b for detecting a change in magnetic flux generated by a reluctor of the rotor to generate a pulse signal Pn.
And a waveform shaping circuit 20 for shaping the output of the signal generator into a desired pulse waveform. The signal generator 3b used for the signal generator 3A includes an iron core having a magnetic pole portion facing the reluctor 3a1 at its tip, a pulsar coil wound around the iron core,
A permanent magnet that is magnetically coupled to the iron core, and is generated in the iron core when the reactor 3a1 starts to oppose the magnetic pole part of the iron core and when the reluctor 3a1 ends opposing the magnetic pole part of the iron core, respectively. Due to the change in the magnetic flux, pulse signals Vs1 and Vs2 having different polarities are induced in the pulsar coil. Instead of using the pulsar coil, a pulse signal may be obtained using a magnetic sensor such as a Hall IC and a waveform shaping circuit that shapes the output of the magnetic sensor into a pulse waveform.

In the example shown in FIG. 1, one of the positive and negative polarity pulse signals Vs1 and Vs2 generated by the signal generator 3A is extracted through the waveform shaping circuit 20, and the extracted signal rises. Is shaped into a faster pulse waveform to obtain a rotation speed detection pulse (rotation speed detection signal) Vf. The rotation speed detection pulse is given to the control calculation unit 5.

In the illustrated example, since only one reluctor of the signal generator 3 is provided, the rotational speed detecting pulse Vf
Is generated at a predetermined position (determined by the mounting angle of the rotor of the signal generator and the mounting position of the signal generator) during one rotation of the crankshaft of the engine.

The target rotation speed setting device 4 includes a reference oscillator 21 whose oscillation frequency is controlled by a crystal oscillator, and a target rotation having a frequency proportional to the target rotation speed by dividing the output frequency of the reference oscillator 21. Frequency divider 22 that outputs number signal Vfo
It consists of

The control operation unit 5 receives the rotation speed detection signal Vf and the target rotation speed signal Vfo, converts the frequency difference F between the two input signals into a voltage signal, and outputs a frequency deviation signal Vfc. A phase detector 23 receives a rotation speed detection signal Vf and a target rotation speed signal Vfo as inputs, detects a phase difference φ between the phase of the rotation speed detection signal Vf and the target rotation speed signal Vfo, and outputs a phase difference signal Vpc. A phase difference detector 24 and an arithmetic circuit 25 which receives a frequency deviation signal Vfc and a phase difference signal Vpc as inputs and outputs a control signal (DC voltage signal) Q whose level changes in accordance with the magnitude of both input signals. ing.

In the above configuration, the frequency deviation detector 2
3 outputs a frequency deviation signal Vfc whose level changes with respect to the frequency deviation F as shown in FIG. FIG.
In the above, F2 is a set lock area, and F1 and F3 are an underspeed area below the lock area F2 and an overspeed area exceeding the lock area, respectively. In the underspeed region F1, the frequency deviation signal Vfc
Holds a high-level constant value (H level), and in the lock region F2, the frequency deviation signal Vfc decreases linearly as the frequency deviation F increases. Further, in the overspeed region F3, the frequency deviation signal Vfc has a low level constant value (L
Level) hold.

In the illustrated example, when the rotation speed of the engine is equal to the target rotation speed (when the frequency deviation F is 0), the frequency deviation signal Vfc has a level H which is half the difference between the H level and the L level. / 2 is set.

The phase difference detector 24 outputs the rotation speed detection signal Vf
And a D / A converter for converting the digital output of the comparator into a voltage signal. The comparator detects the rotation speed detection signal Vf and the target speed signal Vfo. A voltage signal corresponding to the phase difference φ of the rotation speed signal Vfo is output as a phase difference signal Vpc. The phase difference signal Vpc output from the phase difference detector 24 is, for example, as shown in FIG.
As shown in (B), while the phase difference φ changes from 0 to 2π, the phase difference linearly increases from the L level to the H level as the phase difference increases (as the rotation speed decreases), This signal returns to the L level when the phase difference reaches 2π. In this example, when the rotation speed of the engine is equal to the target rotation speed, the phase difference between the rotation speed detection signal and the target rotation speed signal is set to be equal to π. The phase difference signal Vpc has a level H which is １ ／ of the difference between the H level and the L level.
/ 2 is set.

The frequency deviation detector 23 and the phase difference detector 24 which output the above-mentioned signals are connected to the motor by the PL.
In order to perform the L control, a motor control IC provided on the market can be used.

The arithmetic circuit 25 adds the frequency deviation signal Vfc and the phase difference signal Vpc at a predetermined ratio and outputs a control signal Q. The control signal Q holds the maximum level Vmax and the minimum level Vmin when the engine speed is in the underspeed range and in the overspeed range, respectively.
When the rotation speed of the engine is within the lock range, the signal is a DC signal whose level increases and decreases as the levels of the frequency deviation signal and the phase difference signal increase and decrease. Since the frequency deviation detector 23 uses an F / V converter having a delay element, the response to a change in the actual engine speed is poor, but the phase difference detector 24 has no delay element unlike the frequency deviation detector. The phase difference signal output from the phase difference detector 24 changes quickly following the change in the actual rotational speed.

The drive section 6 receives the control signal Q as an input, and supplies a drive current Id pulse-width-modulated by the control signal to the fuel supply amount adjusting device 2. The drive section 6 has a triangular waveform as shown in FIG. Alternatively, a pulse width modulation signal generator 26 that outputs a sawtooth pulse width modulation signal Vt, and a control signal Q
Is compared with the pulse width modulation signal Vt, as shown in FIG. 4 (B), when the pulse width modulation signal Vt exceeds the control signal Q and when the pulse width modulation signal Vt is equal to or less than the control signal Q. The comparator 27 outputs a rectangular wave pulse width modulation control signal Vq whose state (level) is different from the period during which
And a drive circuit 28 which receives the pulse width modulation control signal Vq as an input and supplies a drive current Id having the same waveform as the control signal Vq to the actuator 8.

As shown in the illustrated example, the actuator 8 is configured to increase the fuel supply amount with the increase in the drive current Id, and the drive circuit 28 generates the drive current Id having the same waveform as the pulse width modulation control signal. When the pulse width modulation control signal Vq is configured to output, as shown in FIG. 4B, the pulse width modulation control signal Vq maintains a low level state while the pulse width modulation signal Vt exceeds the control signal Q. It is assumed that the signal is a rectangular wave signal that maintains a high level state while the pulse width modulation signal Vt is equal to or less than the control signal Q.

In the electronic governor device shown in FIG. 1, when the engine speed is lower than the lock speed (in the underspeed range), the control signal Q holds the maximum level. The duty ratio of the width modulation control signal Vq becomes 100%, and the duty ratio of the drive current Id applied to the actuator 8 becomes 100%. This maximizes the fuel supply and increases the engine speed. When the rotation speed increases and enters the lock region, the level of the frequency deviation signal Vfc and the level of the phase difference signal Vpc decrease, so that the level of the control signal Q decreases and the duty ratio of the drive current Id decreases. Decreasing. When the rotation speed matches the target rotation speed, the level of the control signal Q stops changing, and a drive current necessary to maintain the rotation speed at the target rotation speed is supplied to the actuator 8.

When the rotation speed becomes lower than the target rotation speed, the level of the control signal Q decreases, so that the duty ratio of the pulse width modulation control signal Vq increases and the duty ratio of the drive current Id increases. As a result, the fuel supply amount is increased, so that the engine speed increases and returns to the target engine speed.

When the rotational speed enters the overspeed region due to a sudden decrease in the load or the like, the control signal Q is kept at the minimum level, so that the duty ratio of the pulse width modulation control signal Vq becomes 0 and the drive current Id Becomes zero. As a result, the fuel supply amount is reduced to the minimum value, and the engine speed is reduced.

As described above, by providing the control loop for controlling the fuel supply amount so as to keep the phase difference between the rotation speed detection signal and the target rotation speed signal constant, the phase difference detector 24
Since there is no large delay element unlike the / V converter, when the rotation speed of the engine fluctuates, the control signal is rapidly changed by the change of the phase difference signal to perform the rotation speed correction operation. And control responsiveness can be improved. Further, even if a deviation occurs in the control system that controls the frequency deviation to be zero, the deviation is corrected by the control system that controls the phase difference to be constant so that the rotation speed matches the target rotation speed. be able to.

In the above example, the frequency deviation signal Vfc and the phase difference signal Vpc correspond to the frequency deviation F and the phase difference φ, respectively.
3A and 3B, the relationship between the level of the frequency deviation signal Vfc and the frequency deviation F, and the relationship between the level of the phase difference signal Vpc and the phase difference φ are as follows. , Can be changed as appropriate according to the configuration of the subsequent circuit.

In the above example, the control is performed so that the phase difference between the rotation speed detection signal and the target rotation speed signal is constant.
It goes without saying that control may be performed so that the phase difference between the rotation speed detection signal and the target rotation speed signal is made zero.

When a crystal oscillator is used as the reference oscillator 21 as in the above-described example, stable oscillation can be performed without being affected by changes in the ambient temperature and variations in circuit constants. It is possible to prevent the signal from changing due to the ambient temperature and from changing due to variations in the characteristics of the circuit elements, and it is possible to omit the adjustment work at the time of product shipment.

As in the above example, the signal generator having the rotor mounted on the crankshaft of the engine causes the signal to be generated at a constant rotation angle position of the crankshaft of the engine at one rotation of the crankshaft.
When the number of rotation detection pulses is generated at a ratio of the number of rotations and the pulse is used as the rotation number detection signal, the minute fluctuation of the rotation number accompanying the change of the combustion cycle of the internal combustion engine does not affect the control. Therefore, control can be stably performed.

In the above example, the rotor of the signal generator is mounted on the crankshaft of the engine to generate one rotation detection pulse per rotation of the crankshaft. The rotor of the signal generator is attached to the cam shaft that rotates by 間 に during the rotation, and the signal generator uses a rotation detection pulse generated once per rotation of the cam shaft as the rotation detection signal. In the same manner as described above, fine fluctuations in the number of revolutions caused by changes in the combustion cycle of the internal combustion engine do not affect the control, so that the control can be performed stably. When the rotor of the signal generator is mounted on the camshaft and the number of rotation detection pulses is extracted from the signal generator at a rate of one per rotation of the camshaft, the number of rotation detection pulses is equal to that of the crankshaft. It occurs at a rate of one per two rotations.

In other words, in order to perform stable control without being affected by minute fluctuations in the number of revolutions caused by a change in the combustion cycle of the internal combustion engine, a ratio of one crankshaft per rotation or two rotations One per one (0.5 per rotation)
A pulse for detecting the number of revolutions may be generated at the ratio of, and the pulse for detecting the number of revolutions may be used as the number of revolutions detection signal.

In practicing the present invention, it is possible to provide a signal generator for generating a number of rotation detection pulses per rotation and use the output of the signal generator as a rotation detection signal. In this case, in order to prevent detection of fine fluctuations in the rotational speed due to changes in the combustion cycle and to enhance control stability, the combustion cycle fluctuations of the internal combustion engine determined by the above-described equation (1) or (2) Preferably, the rotation speed detector is configured to generate a rotation speed detection pulse having a frequency equal to the frequency.

For example, in a four-cycle four-cylinder internal combustion engine, two explosions are performed at 180-degree intervals during one rotation of the crankshaft, so that the rotation for detecting the rotation speed is generated twice per rotation. When the number detector is configured, the rotation speed detection pulse can be always generated at the same position of the piston, so that the control is performed substantially without being affected by the minute fluctuation of the rotation speed due to the change of the combustion cycle. Can be made. When the target rotational speed is 3600 [rpm], since the engine rotates 60 (= 3600/60) per second, the frequency of the pulse generated at 180-degree intervals in the mechanical angle is 60 × 2 = 120 [Hz].

In general, in the case of an internal combustion engine having four cylinders and n cylinders, every 2 × 360 / n degrees of mechanical angle (n /
(2 times) Since the explosion is performed, if the target rotation speed is No, at equal angular intervals (No / 60) × (n / 2)
An explosion will occur. Therefore, in the case of a 4-cycle n-cylinder internal combustion engine, the combustion cycle fluctuation frequency fx = (No / 60) × (n / 2) defined by the above-mentioned equation (1).
By configuring the rotation speed detector to generate a rotation speed detection pulse having a frequency equal to [Hz], control can be performed substantially without being affected by fine fluctuations in the rotation speed due to changes in the combustion cycle. Can be done.

In the case of a two-cycle engine, an explosion is performed once per revolution in each cylinder.
Since n explosions are performed at equal angular intervals during rotation,
The combustion cycle fluctuation frequency fx defined by the above equation (2)
= (No / 60) x n [Hz] By configuring the rotation speed detector to generate a rotation speed detection pulse having a frequency equal to n [Hz], the influence of a fine rotation speed fluctuation accompanying a change in the combustion cycle can be reduced. Control can be performed without receiving.

As described above, when the rotation speed detector is configured to generate a rotation speed detection pulse having a frequency equal to the combustion cycle fluctuation frequency of the engine, the two-cycle engine and the four-cycle engine can be used. In addition, the control can be stably performed by always generating the rotation speed detection pulse at the same position of the piston.

In the case of a four-cycle engine, as described above, the rotation speed detector is configured to generate a rotation speed detection pulse having a frequency equal to twice the combustion cycle fluctuation frequency. Is also good. Also in this case, since the rotation speed detecting pulse can be always generated at the same position of the piston, the control can be stably performed without being affected by the fine rotation speed fluctuation accompanying the change of the combustion cycle. .

FIG. 2 shows another example of the configuration of an electronic governor for an internal combustion engine according to the present invention. In this example, the output of an AC generator 30 mounted on the internal combustion engine 1 is used as the load of the engine. The rotation speed detector 3 is configured to obtain a rotation speed detection signal from the rotation speed detection signal. In this case, the rotation speed detector 3
For example, a circuit for detecting a zero point of the output of the AC generator 30 to generate a pulse, a waveform shaping circuit for shaping one half-wave of the AC generator 30 into a rectangular wave, and a rise or a rise of the waveform shaping circuit It is composed of a circuit in which a circuit for generating a pulse signal by differentiating the down stream is combined, and outputs a pulse signal having a frequency proportional to the engine speed as a speed detection signal Vf. Other configurations are the same as those in the example shown in FIG.

As shown in FIG. 2, if the rotational speed detection signal is obtained from the output of the AC generator attached to the internal combustion engine as a load, there is no need to provide a special signal generator. Cost can be reduced.

When an AC generator is installed as a load of the internal combustion engine, a current transformer for detecting a load current is provided to drive an ammeter for indicating a current flowing from the generator to the load. There are many. When such a current transformer is provided, a signal having a frequency proportional to the rotation speed may be obtained from the output of the current transformer.

Further, in an ignition device for igniting an internal combustion engine, a signal generator for generating a pulse signal at a predetermined rotation angle position of the engine is used to determine the ignition timing. This signal generator is used as a rotation speed detector. Can also be used.

[0066]

As described above, according to the present invention, the phase difference between the rotation speed detection signal and the target rotation speed signal is made zero or constant by using the phase difference detector having no delay element. Since the control loop for controlling is provided, it is possible to prevent a response delay that may cause a problem in the control system. Since the output of the phase difference detector does not include a ripple, it is possible to prevent the stability of control from being impaired due to the input of the ripple to the control operation unit. In the present invention, in addition to the phase difference detector, a frequency deviation detector is provided to reduce the frequency deviation between the rotation speed detection signal and the target rotation speed signal to a set range or less, and to match the phases of both signals. Or, if a configuration is adopted in which the phase difference between the two signals is controlled to be constant, the rotation speed of the internal combustion engine is quickly increased to the set rotation speed by the control operation of reducing the frequency deviation to a set range or less. After approaching, control is performed so that the phase difference between the rotation speed detection signal and the target rotation speed signal becomes zero or constant, so the time required for the engine rotation speed to settle to the target rotation speed is reduced. Can be shorter.

Further, in the present invention, when the rotation speed detector is configured to obtain the rotation speed detection signal from the output of the AC generator mounted as a load on the internal combustion engine, a special Therefore, the configuration of the control system can be simplified.

Further, in the present invention, a rotation speed detector is provided such that a rotation speed detection pulse having a frequency equal to the combustion cycle fluctuation frequency of the internal combustion engine or a frequency equal to twice the combustion cycle fluctuation frequency is generated as a rotation speed detection signal. With this configuration, the rotation speed detection signal can always be generated at the same position of the piston, so that stable control can be performed without being affected by minute fluctuations in the rotation speed due to changes in the combustion cycle. it can.

Further, in the present invention, even when a signal generator for generating a rotation speed detecting pulse at a rate of one per one rotation or one per two rotations of a crankshaft of an internal combustion engine is used as a rotation speed detector. In addition, stable control can be performed without being affected by minute fluctuations in the number of revolutions due to changes in the combustion cycle.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of an electronic governor device for an internal combustion engine according to the present invention.

FIG. 2 is a block diagram showing another configuration example of the electronic governor device for an internal combustion engine according to the present invention.

FIG. 3A is a diagram illustrating a relationship between a frequency deviation signal and a frequency deviation obtained from a frequency deviation detector used in the electronic governor device of FIG. 1; (B) is a diagram showing a relationship between a phase difference signal obtained from a phase difference detector used in the electronic governor device and the phase difference.

FIG. 4 is a drive unit 6 used in the electronic governor device of FIG.
FIG. 3 is a diagram showing signal waveforms of respective parts of FIG.

FIG. 5 is a block diagram showing a configuration of a conventional electronic governor device for an internal combustion engine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Fuel supply amount adjustment device, 3 ... Rotation speed detector, 4 ... Target rotation speed setting device, 5 ... Control operation unit, 6 ... Drive unit, 7 ... Fuel supply amount adjustment means, 8 ... Actuator ,
Reference numeral 21 denotes a reference oscillator, 22 denotes a frequency divider, 23 denotes a frequency deviation detector, 24 denotes a phase difference detector, 25 denotes an arithmetic circuit, 26 denotes a signal generator for pulse width modulation, 27 denotes a comparator, and 28 denotes a drive circuit.

Claims (7)

[Claims] A fuel supply amount adjusting device for adjusting a fuel supply amount to an internal combustion engine that drives a load; a rotation speed detector that outputs a rotation speed detection signal indicating an actual rotation speed of the internal combustion engine; A target rotation speed setting device that outputs a target rotation speed signal that gives a target rotation speed of the internal combustion engine, and a rotation speed detection signal and a target rotation speed signal that are required to input an actual rotation speed to the target rotation speed. A control operation unit that outputs a control signal that provides an operation amount of the fuel supply amount adjustment device; and a drive current that is required to match an actual rotation speed of the internal combustion engine to a target rotation speed with the control signal as an input. An electronic governor device for an internal combustion engine, comprising: a drive unit provided to a supply amount adjusting device; wherein the rotation speed detector outputs a signal having a frequency proportional to an actual rotation speed of the internal combustion engine as the rotation speed detection signal. To The target rotation speed setter is configured to output a signal having a frequency corresponding to the target rotation speed as the target rotation speed signal, and the control operation unit determines a phase of the rotation speed detection signal and a target rotation speed. A phase difference detector that converts the phase difference between the two signals obtained by digitally comparing the phases of the number signals into a voltage signal and outputs a phase difference signal, and the rotation speed detection signal having the phase difference signal as an input. And an arithmetic circuit for generating, as the control signal, a signal whose level changes according to the phase difference signal so as to make the phase difference of the target rotation speed signal zero or to keep the phase difference constant. An electronic governor device for an internal combustion engine, comprising: 2. A fuel supply amount adjusting device for adjusting an amount of fuel supplied to an internal combustion engine that drives a load, a rotation speed detector that outputs a rotation speed detection signal indicating an actual rotation speed of the internal combustion engine, A target rotation speed setting device that outputs a target rotation speed signal that gives a target rotation speed of the internal combustion engine, and a rotation speed detection signal and a target rotation speed signal that are required to input an actual rotation speed to the target rotation speed. A control operation unit that outputs a control signal that provides an operation amount of the fuel supply amount adjustment device; and a drive current that is required to match an actual rotation speed of the internal combustion engine to a target rotation speed with the control signal as an input. An electronic governor device for an internal combustion engine, comprising: a drive unit provided to a supply amount adjusting device; wherein the rotation speed detector outputs a signal having a frequency proportional to an actual rotation speed of the internal combustion engine as the rotation speed detection signal. To The target rotation speed setter is configured to output a signal having a frequency corresponding to the target rotation speed as the target rotation speed signal, and the control operation unit determines a phase of the rotation speed detection signal and a target rotation speed. A phase difference detector that converts the phase difference between the two signals obtained by digitally comparing the phases of the number signals into a voltage signal and outputs a phase difference signal, and the rotation speed detection signal and the target rotation speed signal. A frequency deviation detector that converts the frequency deviation of both input signals into a voltage signal and outputs a frequency deviation signal,
With the phase difference signal and the frequency deviation signal as inputs, the phase difference is set to zero or constant, and a signal whose level changes according to the phase difference signal and the frequency deviation signal so as to make the frequency deviation zero is output as the control signal. An electronic governor device for an internal combustion engine, comprising: 3. The method according to claim 1, wherein the load is an AC generator, and the rotation speed detector is configured to obtain the rotation speed detection signal from an output of the AC generator. 3. The electronic governor device for an internal combustion engine according to 2. 4. The rotation speed detector is configured to output a rotation speed detection pulse signal having a combustion cycle fluctuation frequency of the internal combustion engine or a frequency twice as high as the combustion cycle fluctuation frequency as the rotation speed detection signal. The electronic governor device for an internal combustion engine according to claim 1 or 2, wherein the electronic governor device is provided. 5. The rotation speed detector comprises a signal generator for generating a rotation speed detection pulse at a rate of one per one rotation or one per two rotations of a crankshaft of the internal combustion engine. 3. The electronic governor device for an internal combustion engine according to 1 or 2. 6. The target rotation speed setting device is configured to divide the output frequency of a reference oscillator whose oscillation frequency is controlled to be constant by a crystal oscillator or a ceramic oscillator to obtain the target rotation speed detection signal. The electronic governor device for an internal combustion engine according to any one of claims 1 to 5, wherein the electronic governor device is provided. 7. A fuel supply amount adjusting device for adjusting an amount of fuel supplied to an internal combustion engine driving a load, a rotation speed detector for outputting a rotation speed detection signal indicating an actual rotation speed of the internal combustion engine, A target rotation speed setting device that outputs a target rotation speed signal that gives a target rotation speed of the internal combustion engine, and a rotation speed detection signal and a target rotation speed signal that are required to input an actual rotation speed to the target rotation speed. A control operation unit that outputs a control signal that provides an operation amount of the fuel supply amount adjustment device; and a drive current that is required to match an actual rotation speed of the internal combustion engine to a target rotation speed with the control signal as an input. An electronic governor device for an internal combustion engine including a drive unit for supplying to a supply amount adjusting device, wherein the target rotation speed setter is a reference oscillator whose frequency is controlled to be constant by a crystal oscillator or a ceramic oscillator,
A frequency divider that divides an output frequency of the reference oscillator and outputs a signal having a frequency corresponding to the target rotation speed as the target rotation speed signal. A signal generator for generating rotation speed detection pulses at equal angular intervals at a rate of one rotation per one rotation of the crankshaft or one rotation per two rotations of the crankshaft; A phase difference detector that converts the phase difference between the two signals obtained by digitally comparing the phase of the rotation speed signal into a voltage signal and outputs the voltage signal;
A frequency deviation detector that receives the rotation speed detection signal and the target rotation speed signal and outputs a voltage signal corresponding to a frequency deviation between both input signals, and outputs an output of the phase difference detector and an output of the frequency deviation detector. An arithmetic circuit that outputs, as the control signal, a signal whose level changes according to the phase difference signal and the frequency deviation signal so that the phase difference is set to zero or constant as input and the frequency deviation is set to zero. An electronic governor device for an internal combustion engine, comprising: